Sediment trap

ABSTRACT

An apparatus for settling sediment from a liquid collected in a drainage pit, including a plurality of spaced apart deflectors which are configured to be inclined in use, the deflectors comprising: an uppermost deflector having an aperture formed in an upper portion thereof so that liquid pooling in the pit can flow through the aperture, a second deflector arranged in use to be at least partially below the uppermost deflector, the second deflector opening into a sediment reservoir at a lower end thereof so that liquid flowing along the second deflector can settle in the sediment reservoir, and a third deflector extending upwardly from the sediment reservoir, the third deflector having an aperture formed in an upper portion thereof so that liquid pooling in the sediment reservoir can flow along the third deflector and through the aperture to exit the pit.

FIELD OF THE INVENTION

The present invention relates to an apparatus for settling sediment from a liquid collected in a drainage pit. More particularly, but not exclusively, the invention relates to a sediment trap.

BACKGROUND OF THE INVENTION

Sediment in stormwater runoff can clog collection systems and pollute waterways in which the runoff flows into. It is desirable to filter sediment from stormwater runoff to reduce the chances of collection systems becoming clogged and to improve the quality of water flowing into waterways. It is also desirable to provide such filtration systems that are simple and cheap to manufacture and can be easily serviced.

Examples of the invention seek to solve, or at least ameliorate, one or more disadvantages of previous sediment traps.

SUMMARY OF THE INVENTION

According to the present invention, there is provided an apparatus for settling sediment from a liquid collected in a drainage pit, including a plurality of spaced apart deflectors which are configured to be inclined in use, the deflectors comprising: an uppermost deflector having an aperture formed in an upper portion thereof so that liquid pooling in the pit can flow through the aperture, a second deflector arranged in use to be at least partially below the uppermost deflector, the second deflector opening into a sediment reservoir at a lower end thereof so that liquid flowing along the second deflector can settle in the sediment reservoir, and a third deflector extending upwardly from the sediment reservoir, the third deflector having an aperture formed in an upper portion thereof so that liquid pooling in the sediment reservoir can flow along the third deflector and through the aperture to exit the pit.

Preferably, each of the deflectors are formed of a plurality of plate-like members which are arranged in an end-to-end configuration. An outer surface of the deflectors can be generally in the form of a pyramid. Preferably, the outer surface is in the form of a truncated pyramid.

Preferably, the uppermost and third deflectors each have a centrally disposed aperture through which the liquid can flow.

An initial sediment reservoir can be defined around a lower edge of the uppermost deflector. The uppermost deflector can have upturned sides which are configured to be received against and generally parallel to walls of the pit.

Preferably, the uppermost deflector spans across the pit. Preferably, the pit has a square cross section.

Preferably, the deflectors are formed from sheet metal or plastic.

Preferably, the apparatus further comprises supports to support the deflectors from each other. Preferably, each of the deflectors are configured to be removably stackable from each other.

According to the present invention, there is also provided an assembly comprising an apparatus of the above described type, the apparatus being installed in a drainage pit.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will be further described, by way of non-limiting example only, with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of apparatus for settling sediment from a liquid collected in a drainage pit of one embodiment of the invention;

FIG. 2 is a perspective view of a lower deflector for use with the apparatus;

FIG. 3 is a perspective view of the apparatus installed in a drainage pit; and

FIG. 4 is a sectioned side view of the apparatus.

DETAILED DESCRIPTION

With reference to FIG. 1, there is shown an apparatus 10 for settling sediment from a liquid collected in a drainage pit, according to a preferred embodiment of the invention. The apparatus 10 is in the form of a sediment trap which is configured to be received in a rectangular stormwater drainage pit and includes a plurality of spaced apart deflectors which are configured to be inclined in use.

The velocity of a liquid flowing upwardly over an inclined plate generally reduces, allowing sediment in the liquid to settle and fall along the plate so as to be collected at a lower portion of the plate. Directing the flow of a liquid in a stormwater drainage pit over inclined plates allows sediment to be removed from the liquid, thereby increasing the quality of liquid flowing from the stormwater drainage pit.

The deflectors include an uppermost deflector 12, a second deflector 14 and a third deflector 16 which are arranged so as to be overlapping and parallel. The uppermost deflector 12 has an aperture 18 formed in an upper portion thereof so that liquid pooling in the pit can flow upward along the first deflector 12 and through the aperture 18. Liquid flowing over an upper edge of first deflector 14 and through the aperture 18 will fall onto the second deflector 14 which is arranged in use to be at least partially below the uppermost deflector 12 so that the liquid will flow downwardly along the second deflector 14. The second deflector 14 opens into a sediment reservoir 20 which is disposed at a lower end of the second deflector 14 so that liquid flowing along the second deflector 14 can settle in the sediment reservoir 20.

The third deflector 16 extends upwardly from the sediment reservoir 20 and has an aperture 22 formed in an upper portion thereof so that liquid flowing from the sediment reservoir can flow upwardly along the third deflector 16 and through the aperture 22 to exit the pit. The liquid flowing through the aperture 22 will exit the pit through conventional means provided in the pit.

Each of the deflectors 12, 14, 16 are formed of a plurality of thin plate-like members which are arranged in an end-to-end configuration to form a single continuous deflector. The stormwater drainage pit has a square cross section and an outermost edge of the deflectors is correspondingly shaped and sized to fit conventional pits. An outer surface of each of the deflectors 12, 14, 16 is generally pyramid shaped and, in the embodiment shown, in the form of a truncated pyramid. The uppermost 12 and third deflectors 16 each have a centrally disposed aperture through which the liquid can flow. An upper portion of the second deflector 14 is generally flat.

The uppermost deflector 12 has upturned sides 24 which are configured to be received against and generally parallel to walls of the pit. The size of the upturned sides 24 is such that a lip 26 which is formed on an upper edge of the upturned sides 24 is disposed higher than a central portion of the uppermost deflector 12. The uppermost deflector 12 spans across the pit and the lip 26 is configured to be in contact with side walls of a stormwater drainage pit so that a majority of the water collected in the drainage pit will pool on top of the uppermost deflector and flow through the aperture 18. An initial sediment reservoir 28 is defined around a lower edge of the uppermost deflector 12 to collect sediment that settles over the uppermost deflector 12.

FIG. 2 illustrates the third deflector 14 used in apparatus 10. The third deflector 14 has radially outwardly extending supports 30 which are disposed along ridges formed on the outer surface of the deflector 14. The supports 30 are configured to support the second and third deflectors 14, 16 from each other. Similarly, the second deflector 14 has supports (not shown) to support the first and second deflectors 12, 14 from each other. In other embodiments, the supports 30 may be in the form of fins or stilts used to prop one deflector from another to maintain a desired separation between them.

The third deflector 14 includes a downwardly extending member 32 and an outer flange 34 extending around a lower perimeter thereof. In use, the downwardly extending member 32 and the outer flange 34, in combination with a side wall of the stormwater drainage pit, define the sediment reservoir 20.

As illustrated in FIG. 3, the apparatus 10 is sized so as to fit within a stormwater drainage pit 36 in a close fitting manner so that the upturned sides 24 are received against walls of the pit 36. In use sediment will settle in the initial sediment reservoir 28 and the sediment reservoir 20 and the apparatus 10 will require cleaning to remove this sediment. Each of the deflectors 12, 14, 16 are removably stackable from each other and once a lid of the pit 36 has been removed, each of the deflectors can be removed, either separately or as an assembly, and the built-up sediment easily scraped, brushed or hosed off. Once the deflectors have been cleaned, they can be replaced in the pit 36 for further use.

The deflectors 12, 14, 16 are formed by folding sheets of material, which in the described embodiment is stainless steel, which are then joined using convention joining processes such as welding for example. It will be appreciated that other suitable materials may be used to form the deflectors. For example, the deflectors may be formed of a plastic material such as high density polyethylene (HDPE) and formed using conventional moulding processes such as vacuum forming.

As shown in FIG. 2, the third deflector 16 is formed of generally triangular sheets having upturned sides. The upturned sides of each sheet are joined to those of the other sheets to form the supports 30.

The embodiments have been described by way of example only and modifications are possible within the scope of the invention disclosed. 

1. An apparatus for settling sediment from a liquid collected in a drainage pit, including a plurality of spaced apart deflectors which are configured to be inclined in use, the deflectors, comprising: an uppermost deflector having an aperture formed in an upper portion thereof so that liquid pooling in the pit can flow through the aperture, a second deflector arranged in use to be at least partially below the uppermost deflector, the second deflector opening into a sediment reservoir at a lower end thereof so that liquid flowing along the second deflector can settle in the sediment reservoir, and a third deflector extending upwardly from the sediment reservoir, the third deflector having an aperture formed in an upper portion thereof so that liquid pooling in the sediment reservoir can flow along the third deflector and through the aperture to exit the pit.
 2. An apparatus according to claim 1, wherein each of the deflectors are formed of a plurality of plate-like members which are arranged in an end-to-end configuration.
 3. An apparatus according to claim 2, wherein an outer surface of the deflectors is generally in the form of a pyramid.
 4. An apparatus according to claim 3, wherein the outer surface is in the form of a truncated pyramid.
 5. An apparatus according to claim 2, wherein the uppermost and third deflectors each have a centrally disposed aperture through which the liquid can flow.
 6. An apparatus according to claim 1, wherein an initial sediment reservoir is defined around a lower edge of the uppermost deflector.
 7. An apparatus according to claim 6, wherein the uppermost deflector has upturned sides which are configured to be received against and generally parallel to walls of the pit.
 8. An apparatus according to claim 1, wherein the uppermost deflector spans across the pit.
 9. An apparatus according to claim 1, wherein the pit has a square cross section.
 10. An apparatus according to claim 1, wherein the deflectors are formed from sheet metal or plastic.
 11. An apparatus according to claim 1, further comprising supports to support the deflectors from each other.
 12. An apparatus according to claim 1, wherein each of the deflectors are configured to be removably stackable from each other.
 13. An assembly comprising an apparatus according to claim 1, the apparatus being installed in a drainage pit. 